This publication provides a description of the concepts, sources and methods used by the ABS in the production of population estimates. Chapter 1 gives an overview of the range of population estimates produced by the ABS and outlines some of the major uses for these population estimates. Chapters 2 and 3 outline the methods and data used to produce population estimates at the national/state and statistical local area (SLA) levels, while Chapter 4 outlines the method used to produce population estimates for customised geography. Chapters 5 to 8 provide additional information of components of population growth and of selected sub-populations. Chapter 9 describes the data sources used to produce population estimates. Further technical details are provided in the Appendices.